Hydraulic snubber for shoulder harness



June 8, 1954 J. L. sAFFLL HYDRAULIC SNUBBER FOR SHOULDER HARNESS Filed March 7, 1952 IN VEN TOR. James L. Saffe/l Patented June 8, 1954 HYDRAULIC SN UBBER FORTSHOULDER" HARNESS '1 James L.- Saffell, Oxnard, Calif.

'1952, Serial No. 275,447 4 Claims.- J; (01. 1551-189);

(Granted under .Title 35, U. S. .Code (1952),

see. 266) Application March ,7,

obviously it may beused in any situation Wherein impact threatens injury to the occupant of a seat.

The invention :aims to produce a harness mechanism which will permit the pilot freedom of movementto a maximum degree compatible with.

specifically the I to reach themthe safety features'of the device. pilot may lean forward in 'his'seat strument to no restraining force; but which strongly opposes sudden forward movement.

It is a further object of the invention to provide a harness mechanism which is completely automatic in that it requires no adjustment or other conscious act on the part of the wearer to make it fully efi'ective when disaster threatens.

It is a further object of t Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following description.

Fig-n1 is-a view' in side-elevation'of a pilots seat equipped I with mechanismembodyin the inven-- tion;-and

Fig. 2 is an enlarged view in vertical-section of -the hydraulic mechanism-.-

The mechanism-shownrin-Figt'l includes a pi-. lotvs seat I0,

date-a pilot in theposition indicated at 14.; The

seat is-fixedly mounted inplace-bymeans indicateddiagrammatically; at El 6. The pilot is provided with-a shoulder-harness ofusual construc- 7 tion; having straps I8 secured to a flexible:cableidescribed hereinafter.-

Onthe rearzplanesurface-of:the backrest I2 is mounted a plate at which supports-a hydraulic cylinderhavinga head 28.1 WithinJthe cylin ing a dependin stem provided with a stop 44 to limit upward movement of the valve.

The piston 30 is urged downwardly toward its retracted position by a compression spring 46 havin little or no initial stress, so that when the piston is at shown in Fig. 2, the spring force on it.

As seen in Fig. 1, the flexible cable comprises a horizontal reach 50 which extends from the harness I8, 29 to a sheave 52 mounted on the upper end of plate 24; a downwardly extending reach 54 extending from sheave 52 to sheave 3t; and an upwardly extendin reach 55 extending from sheave 34 and terminating in a looped end which engages a stud 58 mounted on plate 2 In operation, the respective parts of the harness -oftanywusual. type, comp-rising a cushion portion ll anda backresti 2 to accommo- 1 leans farther forwardly. If the pilot then suddenly returns to his normal posture, spring 46 quickly moves piston 30 to its retracted position, valve 42 opening to permit rapid upward fiow of the fluid. Sudden forward movement of the pilots body is restrained by the rate of fluid flow through port 36, valve 42 remaining seated.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In combination with a vehicle having a chair therein provided with a rigid back and a harness for the chair occupant having its lower portion secured to the chair; a hydraulic cylinder mounted on said back, a piston in said cylinder having a piston rod, a sheave at the outer end of said rod, a flexible cable fixed to said back extending through said sheave and fixed to the upper portion of said harness, said piston being formed with a restricted bypass to permit limited flow of hydraulic fluid past said piston in either direction, a port in said piston, a check valve in said port preventing flow therethrough under influence of tension in said cable but permitting free flow in the opposite direction, and yielding means urging said piston toward retracted position.

2. In combination with a chair having a rigid back and a harness for the chair occupant having its lower portion secured to the chair; a hydraulic cylinder fixedly related to said back, a piston in said cylinder and having a piston rod, anti-friction means at the outer end of said rod, a flexible cable having one end fixed relative to said back and extending into engagement with said anti-friction means and thence to the upper portion of said harness, means securing the other end of said cable to the upper portion of said harness, said piston being formed with a restricted bypass permitting limited flow of hy draulic fiuid past said piston in either direction and a valved port preventing flow therepast under influence of tension in said rod but permitting free fiow in the opposite direction, and yielding means urging said rod to retracted position within said cylinder.

3. In combination with a chair having a rigid 5 back and a harness for the chair occupant having its lower portion secured to the chair; a hydraulic cylinder fixed to said back, a piston movable toward and away from retracted position in said cylinder and having a piston rod formed with an eye at its outer end, a flexible cable having one end fixed to said back and its other end secured to the upper portion of said harness with a loop therebetween slidably related to said eye, said piston being provided with a restricted bypass permitting flow of hydraulic fluid therepast in either direction and a valved port preventing flow therepast under influence of tension in said rod but permitting free flow in the opposite direction, and a spring urging said piston to retracted position.

4. Snubber mechanism for use with a seat and a shoulder harness, comprising a flexible cable secured at One end to the seat and at its other end to the harness with a loop between said ends, and means for maintaining said loop under tension comprising a hydraulic cylinder, a piston freely movable therein toward retracted position and movable but slowly in the other direction, yielding means urging said piston toward re- -tracted position, and a piston rod fixed to said piston and having its outer end formed with an aperture in sliding engagement with said loop.

References Cited in the file of this patent 

